Levulinic acid is a well-known product of hexose acid hydrolysis, and can be inexpensively obtained from cellulose feedstocks. Consequently, it is an attractive starting material in producing many useful 5-carbon compounds such as 5-methyl-2-pyrrolidone, which is used as solvent in industrial applications. U.S. Pat. No. 3,235,562 discloses a vapor phase process of making 5-methyl-2-pyrrolidone from levulinic acid, hydrogen and ammonia in the presence of a hydrogenation catalyst. Barium-promoted copper chromite catalyst can also be used to effect the vapor phase reductive amination of levulinic acid to 5-methyl-2-pyrrolidone, as disclosed by U.S. Pat. No. 3,235,562. U.S. Pat. No. 3,235,562 also discloses a vapor phase process for making 1,5-dimethyl-2-pyrrolidone from levulinic acid, hydrogen, and methyl amine in presence of nickel catalyst supported on kieselguhr. U.S. Pat. No. 3,337,585 discloses a process for making 5-methyl-2-pyrrolidone from levulinic acid and ammonia or ammonium hydroxide in an alkaline reaction medium under carbon monoxide pressure in the range of 1.0 atmospheres to 101 MPa and a temperature in the range of 50° C. to 350° C. British Patent GB 1,036,694 discloses the reductive amination of levulinic acid with ammonia and a subsequent hydrogenation with a Raney Ni catalyst at 150° C. to give 5-methyl-2-pyrrolidone.
5-Methyl-2-pyrrolidone and its 1-linear hydrocarbyl or linear substituted hydrocarbyls have generally been produced by the reaction of alkyl amine with 5-methyl-gamma-butyrolactone. These compounds are used as industrial solvents, in inkjet applications and surfactant applications.
An efficient and low cost process for the production of alkyl and cycloalkyl pyrrolidones would be advantageous.